Holder device for a contact element

ABSTRACT

A contact element of a relay, operative for closing and breaking a power supply circuit, respectively, and comprising a contact element ( 5 ) for establishing a current path over a pair of connection means ( 3, 4 ) in the circuit closing mode, the contact element being received in a socket ( 10 ) that is arranged to be movable relative to the relay, and a spring element ( 22 ) is operative for holding the contact element in the socket such that the contact element is detachable from the socket against the action of said spring element, in a circuit breaking mode.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a holder device for a circuit breakingcontact in a relay, and more specifically to a contact that is operativefor closing and breaking a power supply circuit, respectively. In acircuit closing mode, the contact has a contact element that closes thecurrent path over a pair of conductor connections, said contact elementbeing received in a holder that is movable in the relay and permits thecontact to be released against the action of a spring.

Such contacts typically are used in relays for closing and breaking apower supply circuit, e.g. for a triple-pole alternating current. Therelay or contactor may be manually or electrically controlled. In thelast case, the movement of a magnet is employed to close or to break thecurrent path through the contact element. In addition to the maincontacts, the relay may also comprise secondary contacts and conductorconnections for the control power, which may be controlled manually orelectronically.

In industrial applications these contactors or relays are used as motorswitches, e.g., and are typically arranged in centrals that are suppliedwith operation power current and control power to serve a number ofcurrent consumers. Accordingly, these centrals may include a largenumber of conductors and relays, that require maintenance andreplacement of worn out components such as the contact elements of themain contacts.

In such installations, there is an existing need to reduce serviceinterrupts during maintenance procedures by facilitating the access toworn out components and replacement parts, and to minimize the number ofseparate details required for assembly and disassembly of the relay inconnection with such maintenance.

OBJECT OF INVENTION

The object of the invention is to meet above said need by providing aholder device for a contact element, through which the contact elementmay be released manually without the need for tools, and wherein thecontact element is releasable against the action of a spring element.

According to the invention, this object is met when the contact elementis detachably received in a yoke, and a spring element is anchored inthe yoke to act between said yoke and a carrier wherein the yoke isinserted. In the received position, the contact element is clampedbetween the yoke and said carrier to be released as the yoke isdisplaced relative to the carrier, against the action of the springelement.

The characterizing features of the invention are defined in the attachedclaim 1, and preferred embodiments are defined in the sub-claims.

DRAWINGS

The contact element of the invention is further disclosed below inconnection with an example thereof, and with reference to the attacheddrawings. In the drawings

FIG. 1 is a section through a relay in a plane that is parallel to thepower current direction, in a circuit breaking position;

FIG. 2 is a section along the plane II—II of FIG. 1;

FIG. 3 is a partial end view of a contact element carrier deviceaccording to the invention;

FIG. 4 illustrates the carrier device in a partially broken awayelevation view, and

FIG. 5 is a perspective view showing the inventive yoke to be movablyreceived by the carrier.

DETAILED DESCRIPTION

With reference to the attached drawings, a contactor 1 is illustratedthat is structured for implementation of an embodiment of the invention.

The contactor 1 is an electromagnetic relay operative to control a threephase system power supply. Thus, said contactor 1 comprises connectionsfor system power, contacts, electric magnet, coil and connections forthe control power as known per se, and may further include elements foradapting the contactor to a specified application.

A contactor house 2 is permanently positioned in the current paththrough fastening means, not further shown, so that a bottom side of thehouse is seated on a support structure. Input and output connectionmeans 3,4 are accommodated in the bottom area of the house 2, as bestseen in FIG. 1, for connecting the system power phase conductors to theconductor 1. In the shown embodiment, the connection means 3,4 aretwo-part elements that are fixedly mounted by screws in the house 2, andmay preferably be located in disconnection cells formed in the house 2and equipped with arc-shielding means.

Each pair of connection means 3,4 is associated with a separate contactelement 5. The contact element 5 is supported to be movable from acircuit breaking position shown in FIGS. 1 and 2, to a circuit closingposition wherein the contact element 5 is moved to engagement with theconnection means 3,4. The contact elements 5 are supported in a circuitbreaking bridge or carrier 6, that is movable in the house 2 against theforce of springs 7. The springs 7 are seated in spring guides 8extending out from the bottom of the house 2. The carrier 6 isbridge-shaped to reach transversely over the contactor. Shoulders 9,acting as seats for the springs 7, are formed in the bottom surface ofthe carrier 6. Each contact element 5 is supported in a socket 10,extending out from the bottom surface of the carrier, and seated to bebiased by a spring as is further described below. Preferably, the socket10 is integrally formed in the house 2 to provide separate paths for thesystem power through the contactor 1.

The carrier 6 is formed with a pair of columns 11,12 extending out fromthe upper surface of the carrier. Between upper ends of the columns11,12 there is supported an electromagnet armature 13, resting on seats14 formed on the columns or in separate holders, engaging the columns totransfer the armature movement to the carrier and the contact elements 5in a circuit closing motion.

An electromagnet armature having a magnetized core 15 and a coil 16 issupported on the upper side of the carrier. Moreover, and not furtherdisclosed, the house 2 and the carrier 6 are suitably formed to guideand facilitate the carrier movement between the circuit closing andbreaking positions.

The socket 10, as is best seen in FIGS. 3 to 5, is formed to receive ayoke 17 that is axially movable in the socket 10.

In two opposite sides, said yoke 17 comprises legs 18,19 running inparallel.

In one end, the legs are joined by a transverse portion 20. Said portionis formed to a shoulder 20 adapted for holding a contact element 5 as isfurther described below. In the opposite end, the legs 18,19 comprise aseat 21 for a coiled spring 22, shown in dash-dot lines. In the shownembodiment, said seat 21 is formed by portions of the legs, bent inreverse direction such that one end of the coiled spring 22 is anchoredin the bent portions to be supported between the legs 18,19. The otherend of the spring 22 is free to engage a counter force shoulder formedin the socket 10, which is further described below. Preferably, the yoke17 is integrally formed by bending a sheet material, such as platesteel.

Each leg 18,19 of the yoke has a lug 23, as best seen in FIG. 5. As theyoke is received in the socket 10, said lug 23 interacts with a recessformed in the socket for limiting the yoke motion in the socket andpreventing the yoke from falling out of the socket.

A hollow space 24 is formed to open in the end of the socket 10, whereinthe yoke 17 and the spring 22 are received. Said hollow space 24comprises a passage 25 having two opposing slots 26,27, substantiallytangential to the passage wall. In a bottom of the hollow space, thepassage 25 is longitudinally defined by a pair of shoulders 28,29. As isdescribed below, said shoulders form a counter support for the coiledspring 22 and extend partially within the sectional area of the passage,where a spacing or opening 30 between the shoulders form a transverseconnection between the slots 26,27. Inwardly of shoulders 28,29, apassage 31 runs through the socket 10 to receive the contact element 5such that the contact element is oriented transversally to the passage25 and the socket 10 in the inserted position.

The slots 26,27 reach into the passage 31 and are formed in the outersides with a recess 32 and 33, respectively. In installation, the yoke17 and spring 22 are inserted in the hollow space 24 such that the legs18,19 are received in the slots 26,27. The shoulder 20 is dimensionedrelative to the width of the spacing 30 such that the shoulder is freeto pass through the spacing 30 and pass the shoulders 28,29, until thelugs 23 engage and lock into the recesses 32,33. In this position, anend portion of the yoke 17 as well as the shoulder 20 projects throughthe spacing 30 and partially into the through passage 31, while thecoiled spring 22 is arrested by the shoulders 28,29 so that the yokelugs 23 are biased for engagement with a lower end of the recesses 32and 33, respectively.

In the longitudinal extension of the socket 10, the recesses 32,33 aredimensioned to provide a free space for the lugs 23 so that the yoke 17is permitted a certain freedom of movement in the received position inthe socket 10. Thus, the yoke 17 may be further displaced inwardlyagainst the action of the coiled spring 22, such that the shoulder 20projects further inside the passage 31 for insertion of the contactelement into the yoke 17. As the coiled spring 22 successively ispermitted to return the yoke towards the locking engagement between lugs23 and recesses 32,33, the contact element is clamped to be arrested incontact with the bottom of the passage 31, i.e. against the inner sidesof the shoulders 28,29, before the lugs are stopped by the lower end ofthe recesses.

The contact element 5, as best seen in FIG. 1, comprises an elongateelement that preferably is associated with a controlling, arcuate leafspring 34. A central portion of the leaf spring 34 may be formed with atransverse groove 35, as in the shown embodiment. As the contact elementis received in the yoke 17, said groove 35 engages a ridge 36,correspondingly formed in the shoulder 20. This way, the contact elementand associated leaf spring are pivotally supported about a transverseaxis that permits a certain amount of adjustability in a circuit closingmode, and yet not risking that the contact element is displaced from theyoke 17.

In the illustrated embodiment, three sockets 10 are included in acarrier 6, as best seen in FIG. 2. The carrier is structured to bemovable in a contactor house 2, between a circuit closing and circuitbreaking position, respectively. Shoulders 9 are formed in theintermediate spaces between the sockets 10, said shoulders forming seatsor counter supports for springs 7 that run in guides 8, formed in thecontactor house. In the circuit breaking motion, the springs 7 areoperative for lifting the carrier and the sockets 10 with the contactelements 5 received therein, so that the contact elements are broughtfrom engagement and contact with the conductor connections 3,4. From thedrawings and previous disclosure, it will be understood that in thecircuit closing position the contact elements 5 are biased for contactwith said connections 3,4 through the action of the coiled spring 22, asthe contact elements are brought to engagement with the connections inthe circuit closing motion of the carrier, whereby the yoke 17eventually is displaced relative to the socket 10.

In the foregoing, the invention is described in connection with apreferred embodiment from where modifications of the detailed design ofthe socket, yoke and contact elements are possible without parting fromthe inventive teachings. Thus, the attached claims are drafted to definethe basic inventive solution that meets the above object, which is toprovide a contact arrangement for a relay wherein a minimum number ofseparate elements are manually operated for assembly and disassemblywithout the need for tools.

What is claimed is:
 1. A contact element for a relay, operative forclosing and breaking a power supply circuit, respectively, andcomprising a contact element (5) for establishing a current path over apair of connection means (3,4) in the circuit closing position, saidcontact element (5) being supported by a yoke (17) that is movablyreceived in a socket (10), the yoke (17) enclosing the contact element(5) to be removably received in the socket (10), characterized by aspring element (22) acting between the yoke (17) and a shoulder (28,29)that is formed on the socket (10), wherein the yoke (17) is displaceableagainst the action of said spring (22) for detaching the contact element(5) from the socket, and the yoke (17) and socket (10) havinginteracting locking means (23;32,33) for holding the yoke in the socketwhen the contact element is detached.
 2. The contact element of claim 1,characterized in that the yoke (17) carries said spring (22), one end ofwhich is anchored in a seat (21) formed on the yoke, and the other endof the spring acts upon the shoulder (28,29), formed on the socket, whenthe yoke (17) is received in the socket (10).
 3. The contact element ofclaim 1, characterized in that the shoulder (28,29) has a transverseopening (30) that divides the shoulder in two, and the inner end of theyoke (17) is inserted through the opening as the yoke is received in thesocket (10).
 4. The contact element of claim 1, wherein said lockingmeans of the socket (10) and the yoke (17) comprise snap lock means(23;32,33) that limit the yoke motion relative to the socket and preventthe yoke from falling out of the socket as the contact element (5) isdetached from the socket.
 5. The contact element of claim 1, comprisingsaid yoke (17) formed to have a pair of legs (18,19), in one end joinedby a transverse portion (20), wherein the transverse portion (20) isshaped for pivotal engagement with a leaf spring (34), associated withthe contact element (5) for controlling the same.